Explain the probable allusion in the line "the minister and she would need the whole wide world to breathe in."

Cambridge English Dictionary defines "allusion" as "something that is said or written that is intended to make you think of a particular thing or person:"

The line "the minister and she would need the whole wide world to breathe in" from "Scarlet Letter" is an example of the this literary device.

This line refers to the time when Hester is having an affair with the minister. She feels more comfortable meeting him in the forest where they could be away from the prying eyes of the people and there was no question of intimacy. She says that she feels no sense of guilt while meeting him out in the open forest where she can breathe freely in the open air without the fear of being judged.